Earphone assembly

Abstract: In an earphone assembly, a front cap portion of an outer casing (5) having an electroacoustic transducing device (12) therein has a substantially circular configuration which is greater in diameter than other portions to be able to fit in the cavity of the auricle. The earphone comprises a cord supporting member (4) of a connection cord (3) of the electroacoustic transducing device (12) and a movable member (10) which is pivotable with respect to the outer casing (5). A protruding portion (2a) of the outer casing protrudes peripherally from a peripheral portion of the front cap member thereof. The protruding portion (11) of the movable member (10) cooperates with the peripheral portion of the front cap member of the outer casing (5) to allow the earphone to fit in the cavity of the auricle (9).

Description: The present invention relates to an earphone, and is more particularly directed to a compact earphone assembly having an electroacoustic transducer element for transducing an electric signal derived from an audio device into a sound, the earphone directly fitting in an auricle of a person to allow the person to listen to the sound. In recent years, there has been increasingly used a compact light-weight earphone to fit in a cavity of an auricle instead of a type to be inserted into an external auditory meatus or of a headphone type provided with a headband. Furthermore, in company with popularization of portable audio devices, there is a growing demand for making earphones lighter in weight and with improved attachability. A conventional earphone is shown in Figs. 6A and 6B, of the accompanying drawings. As shown, a housing body 1 incorporates an electroacoustic transducer element, and a front cap member 2 covers the front surface of the electroacoustic transducer element. A connection cord 3 is guided through a cord supporting member 4 from the housing body 1 to the outside to supply on electric power signal from an audio apparatus to the electroacoustic transducer element. An outer casing 5 is of a substantially elliptical shape having a major diameter L1 and a minor diameter L2, which generically comprises the housing body 1 and the front cap member 2. Reference numerals 6, 7, 8, and 9 respectively denote the external auditory meatus, tragus, antitragus, and auricle of a person. The peripheral portion of the front surface of the outer casing 5 has an oval configuration. The reason why the front surface has an oval configuration is that an outer diameter of 17.4 mm is required for internally storing the electroacoustic transducer element when a circular configuration is adopted for the front surface, which results in an increased pressure to be applied to the user. Therefore, an oval shape is adopted for the front surface which has a minimal size. Such an earphone fits in the cavity of the auricle 9, so that the earphone can be retained in the ear in consequence of the effect that the cord supporting member 4 is caught between the tragus 7 and the antitragus 8 and that the outer casing 5 is in contact with both a portion of the tragus 7 on the side of the external auditory meatus 6 and the cavity of the auricle 9. However, since the conventional earphone as described above has a fixed configuration (particularly the dimensions L1 and L2 shown in Fig. 6 A), there has been a problem that the earphone tends easily to fall out when used by a person who has a large auricle, while the earphone gives excessive pain to, or cannot be fitted in, the ear of a person who has a small auricle. The present invention has been developed with a view to mitigating the above described disadvantages and has for its essential objective to provide an improved earphone which is capable of providing a more comfortable attachment by accommodating individual differences in size of the auricle and preventing the earphone from easily falling out or giving pain to the ear. JP-A-02278998 and EP-A-0373816 both disclose earpieces with substantially circular outer housings. Document JP-A-02278998 teaches also the provision of a single projection formed integrally with a moveable front cap and rotatable to adjust the apparent diameter of the earpiece. In order to achieve the aforementioned objective, and according to the present invention, an earphone assembly comprising: a substantially circular outer casing to be fit in a cavity of a human auricle, the outer casing having a housing body and a front outer portion having a peripheral portion, and an electroacoustic, transducer element securely incorporated in said outer casing (5); a cord supporting member for supporting a connection cord extending from the electroacoustic transducer element to outside of the outer casing; and a moveable member of generally annular shape which is rotatable with respect to an outer circumference of the outer casing, characterised in that the peripheral portion of the front outer portion of the outer casing has a substantially circular configuration and is provided with a protruding portion which protrudes outward from a part of the peripheral portion thereof and which is positioned at a specified angle with respect to a reference line (X) of the cord supporting member, and the movable member has a protruding portion which protrudes from a part of a peripheral portion of the movable member further outwardly than the peripheral portion of the front outer portion, whereby, by rotating the movable member for adjusting the position of ist protruding portion, the protruding portion, of the movable member cooperates with the protruding portion of the outer casing and with the peripheral portion of the front outer portion so that the apparent outer diameter of the front peripheral portion between the protruding portion of the front outer portion of the outer casing and the protruding portion of the movable member is changed to be fit in the cavity of an auricle of different sizes. With the above-mentioned construction, the movable member is rotatably adjustable according to the individual difference of the size of the auricle, in particular, the size of the cavity of the auricle, to thereby change the width of the portion to be fitted in the cavity of the auricle. The above arrangement eliminates the tendency that the earphone easily falls out when used by a person who has a large auricle or gives pain to the ear of a person who has a small auricle. In the accompanying drawings:- Fig. 1 is a schematic external view of an earphone in accordance with an embodiment of the present invention; Fig. 2 is a section taken along the line A-A in Fig. 1; Figs. 3A and 3B are perspective views of a housing body of the earphone for the left ear viewed in two directions; Fig. 4 is a perspective view of a movable member of the earphone viewed from the rear surface; Figs. 5A and 5B are plan views with the earphone fitted in the auricle; and, Figs. 6A and 6B are a schematic external view of a conventional earphone and a plan view thereof with the earphone fitted in the auricle. Fig. 1 shows an entire outline of an earphone for a lefthand ear. It is to be noted here that, since an earphone for the righthand ear is symmetrical to that for the lefthand ear, no description is provided therefor. In Figs. 1 and 2, an outer casing 5 comprises a housing body 1 and a front cap member 2, the housing body 1 serving as a case body for housing an electroacoustic transducer element 12 and the front cap member 2 is securely attached to the housing body 1 for covering and fixing the front surface of the electroacoustic transducer element. The front face of the front cap member 2 is covered with a protective net (not shown). The housing body 1 and the front cap member 2 have a substantially circular outer shape. A connection cord 3 is guided in the housing body 1 for supplying an electric power signal derived from an audio device (not shown) to the acoustic transducer. A cord supporting member 4 is integrally formed with the housing body to guide the connection cord 3 extending from the auricle to an audio device. A generally annular movable member 10 is further mounted on the housing body 1 and is rotatable within a specified range of angle (e.g., 60 degrees) around the circumference of the housing body 1. The movable member 10 has a protruding portion 11 protruding outwards and frontwards from a peripheral portion thereof, being formed integrally with the movable member 10. The front cap member 2 is formed in a substantially circumferential configuration and has a protruding portion 2a which protrudes outward in radial direction at a specified angle (e.g., 40 degrees) with respect to a vertical reference line X of the housing body 1 as shown in Fig. 1. The direction of the protruding portion 2a of the front cap member 2 is determined in angle so that the portion 2a is positioned on the side of the external auditory meatus when the outer casing 5 of the earphone is fitted in the cavity of the auricle 9. In more detail, the front cap member 2 is fixed to the housing body 1 so that the protruding portion 2a thereof is positioned at a fixed angle with respect to the cord supporting member 4 so that the protruding portions 2a and 11 cooperate with each other to fit in the auricle of a user without imposing excessive pressure on the user's ear when placed in the concha. The cord supporting member 4 has an approximately cylindrical configuration, having its longitudinal centre line L displaced rightwards in position in the figure with respect to the vertical reference line X of the housing body 1 by a specified dimension of, e.g., 1.5 mm. The movable member 10 is circumferentially rotatable around the periphery of the housing body 1 within a specified range in angle in such a manner that the protruding portion 11 is pivotable in the range between a specified clockwise angle 5(e.g., 15 degrees) and a specified counterclockwise angle (e.g., 45 degrees), i.e., total 60 degrees with respect to a horizontal reference line Y of the housing body 1, where the protruding portion 11 of the movable member is movable in its pivotal range which includes at least a position approximately opposite to the protruding portion 2a of the front cap member 2 of the outer casing. As shown in Fig. 4, a ratchet structure designated by reference numeral 16 and 19 is constructed on the inner surface of the movable member 10 so that the movable member 10 can be engaged with the housing body 1 in a ratchet manner at each interval of a specified angle (e.g. 7.5 degrees), that is, the movable member can be retained at each of nine positions within the rotatable range of, for example, 60 degrees. The following describes in more detail the structure of the earphone assembly according to the embodiment of the present invention with reference to Figs. 2 through 4. In Figs. 2 through 4, the movable member 10 is formed of polyacetal resin, and the protruding portion 11 is formed integrally with the movable member 10, having a plurality of ribs 13 formed integrally with the movable member 10, each of the ribs having substantially the same configuration and protruding inwardly at, for example, five portions of the inner circumference of the movable member 10. An acoustic transducer 12 is securely incorporated within the housing body 1. A plurality of acoustic through holes 14 are formed in a peripheral flange portion of the housing body 1, while a damping cloth 15 made of e.g. urethane resin is provided under the peripheral flange portion of the housing body 1 covering the acoustic holes 14 for giving an acoustic resistance. As shown in Figs. 3A and 4, a ratchet rib 16 is provided integrally with the housing body 1 and protrudes upwardly so as to be engaged with any one of a pair of knurl portions 19 made of polyacetal resin which are formed integrally with the inner surface of the movable member 10. The ratchet structure is constructed by the engagement between the ratchet rib 16 and the knurl portions 19. Each of the knurl portions 19 has nine roots which provides nine engagement positions. The reason why the movable member 10 is provided with a pair of symmetrical knurl portions 19 is that the movable member 10 is allowed to be commonly used as a member for both the lefthand and righthand ears. As shown in Fig. 3B, a pair of stopper receiving edge walls 17 are integrally defined in the peripheral flange 10 portion 21 of the housing body 1, while a stopper rib 18 as shown in Fig. 4 is formed integrally protruding inwardly from an inner surface of the movable member 10. The space defined between the stopper receiving edge walls 17 provides a minimum space for allowing the stopper rib 18 to be movable within a specified angular range of, for example, 60 degrees. As shown in Fig. 2, the inner circumferential ribs 13 of the movable member 10 are engaged with an outer circumferential groove 20 which is formed around an outer circumferential surface of a rear wall portion of the housing body 1 so that the movable member 10 is retained to be rotatable around the circumferential periphery of the housing body 1 without disengagement. It should be noted here that the movable member 10 is engaged with the housing body 1 by snapping from behind the housing body 1. The following describes the operation of the earphone assembly having the above-mentioned construction. Figs. 5A and 5B show conditions where the earphone of the present embodiment is fitted into the auricle, in which Fig. 5A shows the case of a large human auricle, and Fig. 5B shows the case of a small human auricle. In Figs. 5A and 5B, reference numeral 6 denotes an external auditory meatus, 7 a tragus, 8 an antitragus, 9 an auricle, and 9a a concha cavity constituting the auricle cavity. Fig. 5A shows a condition where the protruding portion 11 is pivoted to the lowermost position, i.e., clockwise end of the movable member 10, while Fig. 5B shows a condition where the protruding portion 11 is pivoted to the uppermost position, i.e., counterclockwise end of the movable member 10. In each case, either one or both of the peripheral portion of the front surface of the outer casing 5 and the movable member 10 are in contact with the inner surface of the tragus 7 on the side of the external auditory meatus 6 and the concha cavity 9a, and at the same time the cord supporting member 4 is retained between the tragus 7 and the antitragus 8 to allow the earphone to be fitted in the cavity of the auricle 9. Particularly when the cavity of the auricle 9 is large, the earphone is prevented from falling out by positively abutment of the protruding portion 11 against the concha cavity 9a as shown in Fig. 5A. When the cavity of the auricle 9 is small, a sense of oppression can be eliminated by moving the protruding portion 11 away from the concha cavity 9a as shown in Fig. 5B. In other words, by rotating the movable member 10, the size in diameter of the front peripheral portion (2a, 11) can be changed between the distances La and Lb as shown in Figs. 5A and 5B so that the front peripheral portion is directly put in contact with the auricle 9 when fitting the earphone in the cavity of the auricle 9. In the present embodiment, the acoustic transducer element 12 having a diameter of 14.65 mm is employed, and the minimum diameter of the periphery of the front surface of the front cap member 2 is set to 15.9 mm. Therefore, the distance La is set to 18.2 mm, while the distance Lb is set to 15.9 mm. In the conventional case, since l1 in Fig. 6B is 16.9 mm, a relation of La > l 1 > Lb holds, and accordingly the present embodiment can cover a wide range in size of the auricle. According to the present invention, as described above, an optimum attachability of the earphone can be achieved by adjusting the rotation angle position of the movable member according to the size of the auricle to thereby prevent the earphone from easily falling out when used by a person who has a large auricle or from imposing an excessive pain to the ear of a person who has a small auricle. As described above, a front portion of an outer casing is made to have a substantially circular configuration, being greater in diameter than other portions, to be fitted in a cavity of a human auricle. The earphone assembly is provided with a cord supporting member for supporting a connection cord extending to the electroacoustic transducer element which is fixedly built in the outer casing. A movable member having an outwardly protruding portion is circumferentially rotatable with respect to the circumference of the housing body, while a part of a front cap portion of the outer casing also protrudes outwardly from a peripheral portion thereof. The protruding portion of the movable member cooperates with the peripheral portion of the front cap member to allow the earphone to be fitted in the cavity of the auricle. The above arrangement provides an optimum attachability of the earphone by adjustment of the rotational position of the movable member according to the size of the auricle, effectively preventing the earphone from easily falling out when used by a person who has a large auricle or from imposing an excessive pain to the ear of a person who has a small auricle.

Claims: An earphone assembly comprising: a substantially circular outer casing (5) to be fit in a cavity of a human auricle, the outer casing (5) having a housing body (1) and a front outer portion (2) having a peripheral portion, and an electroacoustic transducer element (12) securely incorporated in said outer casing (5); a cord supporting member (4) for supporting a connection cord (3) extending from the electroacoustic transducer element (12) to outside of the outer casino (5); and a movable member (10) of generally annular shape which is rotatable with respect to an outer circumference of the outer casing (5), characterised in that the peripheral front outer portion (2) of the outer casing(5) has a substantially circular configuration and is provided with a protruding portion (2a) which protrudes outward from a part of the peripheral portion thereof and which is positioned at a specified angle with respect to a reference line (X) of the cord supporting member (4), and the movable member (10) has a protruding portion (11) which protrudes from a part of a peripheral portion of the movable member (10) further outwardly than the peripheral portion of the front outer portion (2), whereby, by rotating the movable member (10) for adjusting the position of its protruding portion (11), the protruding portion (11) of the movable member (10) cooperates with the protruding portion (2a) of the outer casing (5) and with the peripheral portion of the front outer portion (2) so that the apparent outer diameter of the front peripheral portion between the protruding portion (2a) of the front outer portion (2) of the outer casing (5) and the protruding portion (11) of the movable member (10) is changed to be fit in the cavity of an auricle (9) of different sizes. An assembly as claimed in claim 1, wherein the protruding portion (11) of the movable member (10) is movable in its pivotal range which includes at least a position approximately diametrically opposite to the protruding portion (2a) of the outer casing (5). An assembly as claimed in claim 2, wherein the protruding portion (11) of the movable member (10) is pivotable in the range between a specified clockwise angle of approximately 15 degrees and a specified counterclockwise angle of approximately 45 degrees with respect to a horizontal reference line (Y) of the housing body (1). An assembly as claimed in any one of the preceding claims, wherein the protruding portion (11) which protrudes from a peripheral portion of the movable member (10) is formed integrally with the movable member (10). An assembly as claimed in claim 1, wherein the protruding portion (2a) of the outer casing (5) protrudes outward in radial direction at a specified angle with respect, to a vertical reference line (X) of the housing body (1) so that the protruding portion (2a) is positioned on the side of the external auditory meatus when the outer casing (5) of the earphone is fitted in the cavity of the auricle (9). An assembly as claimed in claim 1, wherein the protruding portion (2a) of the outer casing (5) is positioned at a fixed angle with respect to the cord supporting member (4) so that the protruding portion (2a) of the outer casing (5) and the protruding portion (11) of the movable member (10) cooperate with each other to fit in the auricle of a user. An assembly as claimed in claim 5, wherein the cord supporting member (4) has an approximately cylindrical configuration, having its longitudinal centre line (L) displaced in position with respect to the vertical reference line (X) of the housing body (1) by a specified distance. An assembly as claimed in any one of the preceding claims, wherein the housing body (1) is provided with a ratchet rib (16) which protrudes upwards and is integral with the housing body (1), while the movable member (10) is provided with a pair of symmetrical knurl portions (19) which are formed integrally with the inner surface of the movable member (10) thereby to form a ratchet structure by the engagement between the ratchet rib (16) and the knurl portions (19). An assembly as claimed in claim 8, wherein each of the knurl portions (19) has nine roots which provides nine engagement positions so that the movable member (10) is engaged with the housing body (1) in a ratchet manner at each interval of a specified angle, the movable member (10) being retained at each of specified number of positions within the rotatable range. An assembly as claimed in any one of the preceding claims, wherein the movable member (10) has a plurality of ribs (13) formed integrally with the movable member (10), each of the ribs (13) protruding upwardly at specified positions of the inner circumference of the movable member (10). An assembly as claimed in claim 10, wherein the housing body (1) is formed with an outer circumferential groove (20) which is formed around an outer circumferential wall portion of the housing body (1) so that the ribs (13) of the movable member (10) are engaged in the groove (20). An earphone assembly as claimed in any one of the preceding claims, wherein a cut-off portion spaced between a pair of stopper receiving edge walls (17) is defined in a peripheral flange portion (21) of the housing body (1), while an integral stopper rib (18) protrudes inwards from an inner surface of the movable member (10) so that the space between the stopper receiving edge walls (17) is defined to provide a minimum space for receiving the stopper rib (18) to be movable within a specified angular range.

Inventors: KONO KAZUNORI, NAGAYOSHI ATSUSHI, KONO, KAZUNORI, NAGAYOSHI, ATSUSHI
Applicants: MATSUSHITA ELECTRIC IND CO LTD, MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Application year: 1994
Main classification: H04R1
IPC codes: H04R1